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A281060 Number of 5Xn 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards. 1

%I

%S 0,122,1492,3416,7803,16875,32370,59669,107693,191953,339219,595824,

%T 1041681,1814253,3149435,5451162,9409735,16202663,27835100,47716151,

%U 81633286,139397983,237621979,404396106,687167939,1165993033,1975805797

%N Number of 5Xn 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

%C Row 5 of A281056.

%H R. H. Hardin, <a href="/A281060/b281060.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 6*a(n-1) -12*a(n-2) +5*a(n-3) +12*a(n-4) -12*a(n-5) -3*a(n-6) +6*a(n-7) -a(n-9) for n>18

%e Some solutions for n=4

%e ..0..1..0..1. .0..0..1..0. .0..1..1..0. .0..0..1..1. .0..1..0..1

%e ..1..0..1..0. .0..0..1..0. .0..0..1..0. .1..0..0..1. .0..0..0..1

%e ..1..1..0..1. .1..0..1..0. .1..1..1..1. .1..1..1..0. .1..1..0..1

%e ..0..1..0..0. .1..0..1..0. .0..1..0..0. .1..0..1..0. .0..1..0..1

%e ..0..1..1..0. .1..0..1..0. .0..1..1..0. .0..1..0..1. .0..0..1..0

%Y Cf. A281056.

%K nonn

%O 1,2

%A _R. H. Hardin_, Jan 13 2017

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Last modified January 23 03:15 EST 2022. Contains 350504 sequences. (Running on oeis4.)